This invention relates to the method and apparatus for the manufacture of pulleys by an internal spin pulley manufacturing device and process.
Heretofore, one of the methods for the manufacture of pulleys was the use of a spinning metal blank which is deformed by the application of pressure axially and rotationally to create a pulley. The axial pressure administered by the head stock assembly on one side of the blank and the tail stock assembly on the other side of the blank permitted the entire assembly including the blank to rotate. During this rotation, pressure was applied to the outer circumference of the pulley blank in order to form the desired shape of the pulley. This process is not unlike the process used by craftsman at a lathe whereby the desired article is spun on an axis and its shape is controlled by the application of an outside force to the outer surfaces of the object. Examples of prior art utilizing an external application of force to the pulley blank are found in U.S. Pat. No. 3,910,423; U.S. Pat. No. 3,953,995; U.S. Pat. No. 4,055,977; and German Pat. No. 844,587.
The production of pulleys by this spin method utilizing such apparatus is estimated to achieve a production rate of approximately 400 to 500 pieces per hour. In order to improve the quantity of manufacture, a device is needed which eliminates the need for stopping the head stock assembly in order to place the pulley blank in the manufacturing position between the head stock assembly and the tail stock assembly. An attempt has been made to automate the placement of the pulley blank into the assembly through use of automated equipment, disclosed in U.S. Pat. No. 3,910,423. The use of the automated loading equipment with a spin pulley manufacturing device which must stop during each production cycle fails to achieve a maximum quantity of pulleys produced per hour.